Nor'easter, snow and storms forecast across New England through Tuesday

A fast-moving storm pushing through the eastern half of the country could bring big impacts to travel in the Northeast through Tuesday. 

Widespread heavy snowfall is expected across northern Pennsylvania and southern New York late Monday, then southern New England on Tuesday morning, the Weather Prediction Center forecast said late Sunday.

The probability of more than 8 inches of snow ranges from 70-90% along a swath along the Pennsylvania/New York border and across most of Massachusetts, according to the weather prediction center.

Winter storm advisories and warnings also are in effect across Oklahoma, northern Arkansas, southern Missouri and across northern Kentucky.

Just which areas of New England could receive the biggest impacts will be more certain by Monday morning, said David Roth, a meteorologist with the Weather Prediction Center in College Park, Maryland. 

An intensifying Nor’easter along the coast is forecast to cause “moderate coastal flooding” at high tide along the Jersey shore and portions of the New England coast, which has already seen at least two big coastal flood events this winter, as well as higher than normal tides over the weekend. 

Fortunately, the system will be faster-moving, reducing the risks, Roth said. “This doesn’t have the hallmarks of a record event.” 

Rain and wind are forecast early in southern Louisiana early Monday but should clear out in time to prevent any major interruptions to Mardi Gras festivities in New Orleans, he said.

Areas across parts of the southern Appalachians and the southern mid-Atlantic face a risk of excessive rainfall over Monday and into Tuesday with a chance for local flash flooding as the system moves through.

A new low will form over North Carolina that will move off into the mid-Atlantic, Roth said. The path of that movement will help determine where the storm’s worst impacts occur.

“Boston seems like the major city impacted, with a slight chance closer to New York City,” Roth said. 

Onshore winds could push the ocean up into inland rivers and increase the chances for some coastal flooding, he said. 

The storms will see enhanced rainfall because there’s a lot of moisture aloft flowing up over Mexico and moisture moving into the region from the Gulf of Mexico, Roth said. “You’re getting moisture from both oceans, at multiple levels and that’s why we’re experiencing some flash flooding.” 

Warmer than normal sea surface temperatures in the Pacific have been helping boost rainfall in systems coming off the Pacific this winter.